#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <assert.h>
#include "sds.h"
#include "zmalloc.h"

/* 创建长度为initlen, 内容为init的sds字符串:
    1. 判断init内容使用malloc或者calloc创建方式
    2. 将init内容拷贝到sdshdr->buf中, 设置\0结尾
    3. sdshdr->len保存字符长度, free表示空闲的内存字节数
*/
sds sdsnewlen(const void *init, size_t initlen) {
    struct sdshdr *sh;
    if (init) {
        sh = zmalloc(sizeof(struct sdshdr) + initlen + 1);
    } else {
        sh = zcalloc(sizeof(struct sdshdr) + initlen + 1);
    }
    if (sh == NULL) return NULL;
    sh->len = initlen;
    sh->free = 0;
    if (initlen && init)
        memcpy(sh->buf, init, initlen);
    sh->buf[initlen] = '\0';
    return (char*)sh->buf;
}

/* 创建一个空字符 */
sds sdsempty(void) {
    return sdsnewlen("", 0);
}

/* 创建内容为init的sds */
sds sdsnew(const char *init) {
    size_t initlen = (init == NULL) ? 0 : strlen(init);
    return sdsnewlen(init, initlen);
}

/* 创建一个重复的sds */
sds sdsdup(const sds s) {
    return sdsnewlen(s, sdslen(s));
}

/* 释放一个sds */
void sdsfree(sds s) {
    if (s == NULL) return;
    zfree(s - sizeof(struct sdshdr));
}

/* 更新sds的长度 */
void sdsupdatelen(sds s) {
    struct sdshdr *sh = (void*) (s - sizeof(struct sdshdr));
    int reallen = strlen(s);
    sh->free += (sh->len - reallen);
    sh->len = reallen;
}

/* 清除sds内容: 
    1. 设置len和free
    2. 设置哨兵字符
*/
void sdsclear(sds s) {
    struct sdshdr *sh = (void*)(s - sizeof(struct sdshdr));
    sh->free += sh->len;
    sh->len = 0;
    sh->buf[0] = '\0';
}

/* 为sds增加新的长度: 
    * 首先判断free和addlen大小
    * 如果free过小, 需要重新分配addlen
    * 计算总的newlen = 原来的len + addlen
    * 这里采用预分配的方式来分配newlen
    * 最后采用realloc重新分配newlen这么多的内容
    * 重新设置sds的len和free
*/
sds sdsMakeRoomFor(sds s, size_t addlen) {
    struct sdshdr *sh, *newsh;
    size_t free = sdsavail(s);
    size_t len, newlen;

    if (free >= addlen) return s;
    len = sdslen(s);
    sh = (void*) (s - sizeof(struct sdshdr));
    newlen = (len + addlen);
    if (newlen < SDS_MAX_PREALLOC)
        newlen *= 2;
    else
        newlen += SDS_MAX_PREALLOC;
    newsh = zrealloc(sh, sizeof(struct sdshdr) + newlen + 1);
    if (newsh == NULL) return NULL;
    newsh->free = newlen - len;
    return newsh->buf;
}

/* 移除sds空闲的空间:
    * 本质上就是重新分配内存, 采用realloc设置长度
    * 最后设置free为0
*/
sds sdsRemoveFreeSpace(sds s) {
    struct sdshdr *sh;
    sh = (void*) (s - sizeof(struct sdshdr));
    sh = zrealloc(s, sizeof(struct sdshdr) + sh->len + 1);
    sh->free = 0;
    return sh->buf;
}

/* 计算sds分配的所有size 
    * len + free + sizeof(struct sdshdr) + 1
*/
size_t sdsAllocSize(sds s) {
    struct sdshdr *sh = (void*) (s - sizeof(struct sdshdr));
    return sizeof(*sh) + sh->len + sh->free + 1;
}

/*  增加sds的内容长度:
    * len增加incr
    * free减小incr
    * 重新设置\0
*/
void sdsIncreLen(sds s, int incr) {
    struct sdshdr *sh = (void*) (s - sizeof(struct sdshdr));
    assert(sh->free >= incr);
    sh->len += incr;
    sh->free -= incr;
    assert(sh->free >= 0);
    s[sh->len] = '\0';
}


/* 增加sds的长度到len:
    * 如果长度已经足够, 直接返回
    * 如果长度不够, 计算需要新增的长度, 使用MakeRoom方法增加
    * 将新增的部分重置
    * 计算总长度
    * 设置目前的长度
*/
sds sdsgrowzero(sds s, size_t len) {
    struct sdshdr *sh = (void*) (s - sizeof(struct sdshdr));
    size_t totlen, curlen = sh->len;
    if (len <= curlen) return s;
    sdsMakeRoomFor(s, len - curlen);
    if (s == NULL) return NULL;
    sh = (void*) (s - sizeof(struct sdshdr));
    memset(s + curlen, 0, (len - curlen + 1));
    totlen = sh->len + sh->free;
    sh->len = len;
    sh->free = totlen - sh->len;
    return s;
}

/* sds s拼接长度为len的t:
    * 增加空间
    * 拷贝内容
    * 设置新的长度
*/
sds sdscatlen(sds s, const void *t, size_t len) {
    struct sdshdr *sh;
    size_t curlen = sdslen(s);

    s = sdsMakeRoomFor(s, len);
    if (s == NULL) return NULL;
    sh = (void*) (s - sizeof(struct sdshdr));
    memcpy(s + curlen, t, len);
    sh->len = curlen + len;
    sh->free = sh->free - len;
    s[curlen + len] = '\0';
    return s;
}

/* 拼接字符串 */
sds sdscat(sds s, const char *t) {
    return sdscatlen(s, t, strlen(t));
}

/* 拼接sds */
sds sdscatsds(sds s, const sds t) {
    return sdscatlen(s, t, sdslen(t));
}

/* 拷贝长度为len的t到s中 */
sds sdscpylen(sds s, const char *t, size_t len) {
    struct sdshdr *sh = (void*) (s - sizeof(struct sdshdr));
    size_t totlen = sh->free + sh->len;
    if (totlen < len) {
        s = sdsMakeRoomFor(s, len - sh->len);
        if (s == NULL) return NULL;
        sh = (void*) (s - sizeof(struct sdshdr));
        totlen = sh->free + sh->len;
    }
    memcpy(s, t, len);
    s[len] = '\0';
    sh->len = len;
    sh->free = totlen - len;
    return s;
}

/* 将字符串t拷贝到sds s中 */
sds sdscpy(sds s, const char *t) {
    return sdscpylen(s, t, strlen(t));
}

/* vsnprintf函数将可变参数列表中的数据格式化打印到缓冲区:
    * 如果超出了最大长度, 则会截断末尾填\0
    * 函数返回实际打印的长度
    因此为了寻找合适的最大size, 采用len - 2位进行标识


*/
sds sdscatvprintf(sds s, const char *fmt, va_list ap) {
    va_list cpy;
    char *buf, *t;
    size_t buflen = 16;

    while (1) {
        buf = zmalloc(buflen);
        if (buf == NULL) return NULL;
        buf[buflen - 2] = '\0';
        va_copy(cpy, ap);
        vsnprintf(buf, buflen, fmt, cpy);
        if (buf[buflen - 2] != '\0') {
            zfree(buf);
            buflen *= 2;
            continue;
        }
        break;
    }

    t = sdscat(s, buf);
    zfree(buf);
    return t;
}

/*  格式化拼接: 
    * va_start
    * use va_list
    * va_end
*/
sds sdscatprintf(sds s, const char *fmt, ...) {
    va_list ap;
    char *t;
    va_start(ap, fmt);
    t = sdscatvprintf(s, fmt, ap);
    va_end(ap);
    return t;
}


/* 将s中包含cset总的字符trim掉, Trim只在头尾发生:
    * 记录头尾指针
    * 重新回复sds的各项信息
*/
sds sdstrim(sds s, const char *cset) {
    struct sdshdr *sh = (void*) (s - sizeof(struct sdshdr));
    char *start, *end, *sp, *ep;
    size_t len;
    sp = start = s;
    ep = end = s + sdslen(s) - 1;
    while (sp <= end && strchr(cset, *sp)) sp++;
    while (ep >= start && strchr(cset, *ep)) ep--;

    len = (sp > ep) ? 0 : ep - sp + 1;
    if (sh->buf != sp) memmove(sh->buf, sp, len);
    sh->buf[len] = '\0';
    sh->free = sh->free + sh->len - len;
    sh->len = len;
    return s;
}

/* 获取范围在start - end之间的sds:
    * 允许start和end为负数
    * 需要重新计算sds的长度等信息
*/
sds sdsrange(sds s, int start, int end) {
    struct sdshdr *sh = (void*) (s - sizeof(struct sdshdr));
    size_t newlen, len = sdslen(s);

    if (len == 0) return;
    if (start < 0) {
        start += len;
        if (start < 0) start = 0;
    }

    if (end < 0) {
        end += len;
        if (end < 0) end = 0;
    }
    newlen = (start > end) ? 0 : end - start + 1;
    if (newlen != 0) {
        if (start >= (signed) len) {
            newlen = 0;
        } else if (end >= (signed) len) {
            end = len - 1;
            newlen = (start > end) ? 0 : end - start + 1;
        }
    } else {
        start = 0;
    }

    if (start && newlen) memmove(sh->buf, sh->buf + start, newlen);
    sh->buf[newlen] = '\0';
    sh->free = sh->free + sh->len - newlen;
    sh->len = newlen;
    return s;
}


void sdstolower(sds s) {
    int len = sdslen(s), j;
    for (j = 0; j < len; j++) s[j] = tolower(s[j]);
}

void sdstoupper(sds s) {
    int len = sdslen(s), j;
    for (j = 0; j < len; j++) s[j] = toupper(s[j]);
}


int sdscmp(const sds s1, const sds s2) {
    size_t l1, l2, minlen;
    int cmp;
    l1 = sdslen(s1);
    l2 = sdslen(s2);
    minlen = (l1 < l2) ? l1 : l2;
    cmp = memcmp(s1, s2, minlen);
    return cmp == 0 ? l1 - l2 : cmp;
}

sds *sdssplitlen(const char *s, int len, const char *sep, int seplen, int *count) {
    int elements = 0, slots = 5, start = 0, j;
    sds *tokens;

    if (seplen < 1 || len < 0) return NULL;
    tokens = zmalloc(slots * sizeof(sds));
    if (tokens == NULL) return NULL;

    if (len == 0) {
        *count = 0;
        return tokens;
    }

    /* 扫描直到末尾的\0 */
    for (j = 0; j < len - seplen + 1; j++) {
        if (slots < elements + 2) {
            sds *newtokens;
            slots *= 2;
            newtokens = zrealloc(tokens, slots * sizeof(sds));
            if (newtokens == NULL) goto cleanup;
            tokens = newtokens;
        }

        if ((seplen == 1 && *(s + j) == sep[0]) || (memcmp(s + j, sep, seplen) == 0)) {
            tokens[elements] = sdsnewlen(s + start, j - start);
            if (tokens[elements] == NULL) goto cleanup;
            elements++;
            start = j + seplen;
            j = j + seplen - 1;
        }
    }

    tokens[elements] = sdsnewlen(s + start, len - start);
    if (tokens[elements] == NULL) goto cleanup;
    elements++;
    *count = elements;
    return tokens;

cleanup:
    {
        int i;
        for (i = 0; i < elements; i++) sdsfree(tokens[i]);
        zfree(tokens);
        *count = 0;
        return NULL;
    }
}


void sdsfreesplitres(sds *tokens, int count) {
    if (!tokens) return;
    while (count--)
        sdsfree(tokens[count]);
    zfree(tokens);
}

sds sdsfromlonglong(long long value) {
    char buf[32], *p;
    unsigned long long v;

    v = (value < 0) ? -value : value;
    p = buf + 31;
    do {
        *p-- = '0' + v % 10;
        v /= 10;
    } while (v);
    if (value < 0) *p-- = '-';
    p++;
    return sdsnewlen(p, 32 - (p - buf));
}

sds sdscatrepr(sds s, const char *p, size_t len) {
    s = sdscatlen(s, "\"", 1);
    while (len--) {
        switch (*p) {
            case '\\':
            case '"':
                s = sdscatprintf(s, "\\%c", *p);
                break;
            case '\n': s = sdscatlen(s, "\\n", 2); break;
            case '\r': s = sdscatlen(s, "\\r", 2); break;
            case '\t': s = sdscatlen(s, "\\t", 2); break;
            case '\a': s = sdscatlen(s, "\\a", 2); break;
            case '\b': s = sdscatlen(s, "\\b", 2); break;
            default:
                if (isprint(*p))
                    s = sdscatprintf(s, "%c", *p);
                else
                    s = sdscatprintf(s, "\\x%02x", (unsigned char) *p);
                break;
        }
        p++;
    }
    return sdscatlen(s, "\"", 1);
}


int is_hex_digit(char c) {
    return (c >= '0' && c <= '9') || (c >= 'a' || c <= 'f') ||
        (c >= 'A' && c <= 'F');
}

int hex_digit_to_int(char c) {
    switch (c) {
    case '0':
    case '1':
    case '2':
    case '3':
    case '4':
    case '5':
    case '6':
    case '7':
    case '8':
    case '9': return c - '0';
    case 'a': case 'A': return 10;
    case 'b': case 'B': return 11;
    case 'c': case 'C': return 12;
    case 'd': case 'D': return 13;
    case 'e': case 'E': return 14;
    case 'f': case 'F': return 15;
    default: return 0;
    }
}


/* 本质上是用来分隔参数, 其中参数包括单引号和双引号分隔的参数:
    1. 两种情况要分开处理
    2. 要处理特殊情况:
        * \xBC 16进制字符
        * \t \n等转义字符
    3. 参数数目保存在argc中
    4. 输出结果保存在vector中, 由调用者释放
 */
sds *sdssplitargs(const char *line, int *argc) {
    const char *p = line;
    char *current = NULL;
    char **vector = NULL;
    *argc = 0;
    while (1) {
        while (*p && isspace(*p)) p++;
        if (*p) {
            int inq = 0, insq = 0, done = 0;
            if (current == NULL) current = sdsempty();
            while (!done) {
                if (inq) {
                    if (*p == '\\' && *(p + 1) == 'x' && is_hex_digit(*(p + 2)) && is_hex_digit(*(p + 3))) {
                        unsigned char byte;
                        byte = hex_digit_to_int(*(p + 2) * 16) + hex_digit_to_int(*(p + 3));
                        current = sdscatlen(current, (char*)&byte, 1);
                        p += 3;
                    }
                    else if (*p == '\\' && *(p + 1)) {
                        char c;
                        p++;
                        switch (*p) {
                            case 'n': c = '\n'; break;
                            case 'r': c = '\r'; break;
                            case 't': c = '\t'; break;
                            case 'b': c = '\b'; break;
                            case 'a': c = '\a'; break;
                            default: c = *p; break;
                        }
                        current = sdscatlen(current, &c, 1);
                    }
                    else if (*p == '"') {
                        if (*(p + 1) && !isspace(*(p + 1))) goto err;
                        done = 1;
                    }
                    else if (!*p) {
                        goto err;
                    }
                    else {
                        current = sdscatlen(current, p, 1);
                    }
                }
                else if (insq) {
                    if (*p == '\\' && *(p + 1) == '\'') {
                        p++;
                        current = sdscatlen(current, "'", 1);
                    }
                    else if (*p == '\'') {
                        if (*(p + 1) && !isspace(*(p + 1))) goto  err;
                        done = 1;
                    }
                    else if (*p) {
                        goto err;
                    }
                    else {
                        current = sdscatlen(current, p, 1);
                    }
                }
                else {
                    switch (*p) {
                        case ' ':
                        case '\n':
                        case '\r':
                        case '\t':
                        case '\0':
                            done = 1;
                            break;
                        case '"':
                            inq = 1;
                            break;
                        case '\'':
                            insq = 1;
                            break;
                        default:
                            current = sdscatlen(current, p, 1);
                            break;
                    }
                }

                if (*p) p++;
            }

            vector = zrealloc(vector, ((*argc + 1) * sizeof(char*)));
            vector[*argc] = current;
            (*argc)++;
            current = NULL;
        } else {
            if (vector == NULL) vector = zmalloc(sizeof(void*));
            return vector;
        }
    }

err:
    while ((*argc)--) sdsfree(vector[*argc]);
    zfree(vector);
    if (current) sdsfree(current);
    *argc = 0;
    return NULL;
}

void sdsIncrLen(sds s, int incr) {
    struct sdshdr *sh = (void*) (s - sizeof(struct sdshdr));
    assert(sh->free >= incr);
    sh->len += incr;
    sh->free -= incr;
    assert(sh->free >= 0);
    s[sh->len] = '\0';
}

/* 将s按照from -> to表进行映射 */
// sds sdsmapchars(sds s, const char *from, const char *to, size_t setlen) {
//     size_t j, i, l = sdslen(s);

//     for (j = 0; j < l; j++) {
//         for (i = 0; i < setlen; i++) {
//             if (s[j] == from[i]) {
//                 s[j] = to[i];
//                 break;
//             }
//         }
//     }
//     return s;
// }

/* 另外一种实现方式 */
sds sdsmapchars(sds s, const char *from, const char *to, size_t setlen) {
    size_t j, i, l = sdslen(s);
    char map[256];
    for (i = 0; i < setlen; i++) map[from[i]] = to[i]; // 构造映射表
    for (j = 0; j < l; j++) s[j] = map[s[j]];
    return s;
}

/* 采用seq连接argc个字符串 */
sds sdsjoin(char **argv, int argc, char *sep) {
    sds join = sdsempty();
    int j;
    for (j = 0; j < argc; j++) {
        join = sdscat(join, argv[j]);
        if (j != argc - 1) join = sdscat(join, sep);
    }
    return join;
}

#include "testhelp.h"
#include <stdio.h>

int main(void) {
    {
        struct sdshdr *sh;
        sds x = sdsnew("foo"), y;

        test_cond("Create a string and obtain the length",
            sdslen(x) == 3 && memcmp(x,"foo\0",4) == 0)
        sdsfree(x);

        x = sdsnewlen("foo",2);
        test_cond("Create a string with specified length",
            sdslen(x) == 2 && memcmp(x,"fo\0",3) == 0)

        x = sdscat(x,"bar");
        test_cond("Strings concatenation",
            sdslen(x) == 5 && memcmp(x,"fobar\0",6) == 0);

        x = sdscpy(x,"a");
        test_cond("sdscpy() against an originally longer string",
            sdslen(x) == 1 && memcmp(x,"a\0",2) == 0)

        x = sdscpy(x,"xyzxxxxxxxxxxyyyyyyyyyykkkkkkkkkk");
        test_cond("sdscpy() against an originally shorter string",
            sdslen(x) == 33 &&
            memcmp(x,"xyzxxxxxxxxxxyyyyyyyyyykkkkkkkkkk\0",33) == 0)


        sdsfree(x);
        x = sdscatprintf(sdsempty(),"%d",123);
        test_cond("sdscatprintf() seems working in the base case",
            sdslen(x) == 3 && memcmp(x,"123\0",4) ==0)

        sdsfree(x);
        x = sdstrim(sdsnew("xxciaoyyy"),"xy");
        test_cond("sdstrim() correctly trims characters",
            sdslen(x) == 4 && memcmp(x,"ciao\0",5) == 0)

        y = sdsrange(sdsdup(x),1,1);
        test_cond("sdsrange(...,1,1)",
            sdslen(y) == 1 && memcmp(y,"i\0",2) == 0)

        sdsfree(y);
        y = sdsrange(sdsdup(x),1,-1);
        test_cond("sdsrange(...,1,-1)",
            sdslen(y) == 3 && memcmp(y,"iao\0",4) == 0)

        sdsfree(y);
        y = sdsrange(sdsdup(x),-2,-1);
        test_cond("sdsrange(...,-2,-1)",
            sdslen(y) == 2 && memcmp(y,"ao\0",3) == 0)

        sdsfree(y);
        y = sdsrange(sdsdup(x),2,1);
        test_cond("sdsrange(...,2,1)",
            sdslen(y) == 0 && memcmp(y,"\0",1) == 0)

        sdsfree(y);
        y = sdsrange(sdsdup(x),1,100);
        test_cond("sdsrange(...,1,100)",
            sdslen(y) == 3 && memcmp(y,"iao\0",4) == 0)

        sdsfree(y);
        y = sdsrange(sdsdup(x),100,100);
        test_cond("sdsrange(...,100,100)",
            sdslen(y) == 0 && memcmp(y,"\0",1) == 0)

        sdsfree(y);
        sdsfree(x);
        x = sdsnew("foo");
        y = sdsnew("foa");
        test_cond("sdscmp(foo,foa)", sdscmp(x,y) > 0)

        sdsfree(y);
        sdsfree(x);
        x = sdsnew("bar");
        y = sdsnew("bar");
        test_cond("sdscmp(bar,bar)", sdscmp(x,y) == 0)

        sdsfree(y);
        sdsfree(x);
        x = sdsnew("aar");
        y = sdsnew("bar");
        test_cond("sdscmp(bar,bar)", sdscmp(x,y) < 0)

        {
            int oldfree;

            sdsfree(x);
            x = sdsnew("0");
            sh = (void*) (x-(sizeof(struct sdshdr)));
            test_cond("sdsnew() free/len buffers", sh->len == 1 && sh->free == 0);
            x = sdsMakeRoomFor(x,1);
            sh = (void*) (x-(sizeof(struct sdshdr)));
            test_cond("sdsMakeRoomFor()", sh->len == 1 && sh->free > 0);
            oldfree = sh->free;
            x[1] = '1';
            sdsIncrLen(x,1);
            test_cond("sdsIncrLen() -- content", x[0] == '0' && x[1] == '1');
            test_cond("sdsIncrLen() -- len", sh->len == 2);
            test_cond("sdsIncrLen() -- free", sh->free == oldfree-1);
        }
    }
    test_report()
    return 0;
}


